In 2008, Sandra Critelli shot this excellent photo of Golden Rays off the Mexican coast:

She said: "It was an unreal image, very difficult to describe. The surface of the water was covered by warm and different shades of gold and looked like a bed of autumn leaves gently moved by the wind.

"It's hard to say exactly how many there were but in the range of a few thousand.

"We were surrounded by them without seeing the edge of the school and we could see many under the water surface too.

Golden Rays grow up to seven feet across and migrate within the Caribbean.